Expansion joint and cap



March 7, 1939. R R ROBERTSON 2,149,466

EXPANSION JOINT AND CAP I Filed May 3, 1937 2 Sheets-Sheet l gag ROBERT R. ROBERTSON March 7, 1939. R. R. ROBERTSON EXPANSION JOINT AND CAP Filed May 3, 1937 2 Sheets-Sheet 2 ROBERT R. ROBERTSON Patented Mar. 7, 1939 UNITED STATES PATENT OFFICE The Translode Joint Company,

Chicago Heights, 111., a corporation of Illinois Application May 3, 1937, Serial No. 140,283

4 Claims.

The present invention pertains to an improved road expansion joint and cap adapted to be imbedded between adjacent concrete road slabs, said joint including in combination a precast 5 plastic filler board secured to one side of a metal plate having a supporting base for supporting the joint on a road subgrade, said filler board and plate being apertured at spaced intervals for the reception of adjustable load transmission units including dowel bars mounted in reverse overlapping relation, with the overlapping ends thereof engaged in pocket-forming parts of double looped slidably interfitting sections, portions of which project through the metal plate and the filler board. The improved load transmission joint includes in its combination an improved top or cap engageable over the top margins of the metal plate and the filler board, with one side of the cap so formed that an anchoring plate or flange is imbedded in the concrete on'one side of the joint to permit opening and closing of the cap with the contraction and expansion of the road slabs between which the improved joint is imbedded.

2 It is an object of this invention to provide an improved road expansion joint including in combination a main metal plate having a filler board cemented to one side thereof, said plate and board having openings therethrough at spaced intervals 30 for the reception of load transmission units for connecting the road slabs on opposite sides of the joint, said plate having formed at the lower margin thereof a supporting base, while the upper margins of the plate and the filler board secured 35 thereto are covered by an improved flexible cap,

one side of which is formed to be anchored in a concrete road slab on one side of the joint to permit opening and closing of the cap from one side thereof with the expansion and contraction of the road slabs between which the joint is imbedded.

It is also an object of this invention to provide an improved expansion joint including a metal plate and a preformed plastic filler board which are cemented together, and both of which are provided with openings at spaced intervals for the reception of interfitting sections of load transmission units including fiat dowel bars, with the dowel bars of a unit imbedded in the adjacent concrete road slabs on opposite sides of the joint for the transmission of loads through the joint from one slab to the other, said joint being adapted to be supported on a road subgrade, before thepouring of concrete, by means of a supporting base forming part of the joint plate, or by means of individual supporting shoes arranged in spaced relation along the bottom margins of the joint plate and filler board.

It is a further object of this invention to provide an improved typeof. road expansion joint including in combination an apertured filler board having cemented to one side thereof an apertured metal plate provided with means for anchoring the plate to a concrete road slab on one side of the joint and with said apertured filler board and plate having transversely adjustable load transmission units projecting therethrough and anchored in the adjacent road slabs on opposite sides of the joint for the transmission of loads from one side of the joint to the other, said joint including a projecting cap engaged over the top margins of the filler board and the metal plate, with one side of. the cap having an anchoring flange which is'imbedded in one of the concrete slabs only to permit opening and closing of the cap from one side only.

It is furthermore an object of this invention to provide an improved road expansion joint provided with a core unit having load transmis- I sion units projecting through the core unit at spaced intervals along the joint for connecting adjacent slabs through the joint, said joint being provided with improved copper closure caps on the top and bottom, or on the top only, if so desired, said caps or cap being formed with an anchoring flange at one side thereof only to anchor the caps or cap in a road slab at one side of the joint to cause opening and closing of the caps or cap with the contraction and the expansion of the road slab due to temperature changes or other causes.

Another object of the invention is the provision of an improved type of copper cap for a road expansion joint, said cap including the side flanges, one of which is larger than the other and is provided with an anchoring flange extension for imbedding in the concrete on one side of the joint, while the smaller side flange of the cap is adapted to be engaged between a core plate and the concrete to which the core plate is anchored, said cap construction permitting opening and closing of the cap with the contraction and expansion of the road slabs. 7

Itis also an object of this invention to provide a road expansion joint wherein a filler board and plate are constructed to be anchored to a concrete slab on one side of the joint, with said filler board and plate having load transmission units projecting therethrough at spaced intervals for connecting the slabs on opposite sides of the joint for the transmission of loads, said filler board and plate having the lower and upper margins thereof covered by means of closure caps provided with anchoring extensions on one side thereof for anchoring in concrete on one side of the joint, while the opposite sides of the caps are positioned to be imbedded betweenthe concrete of the adjacent section and the core plate for movement therewith whereby the upper and lower caps are adapted tobe opened and closed thereof which are provided between load transwith the contraction and expansion of the road slabs between which the joint is imbedded.

A further object of the invention is the provision of a road expansion joint having'load transmission units projecting therethrough at spaced intervals, with said joint adapted to be supported in position on a road subgrade prior to the pour ing of concrete by means of apertured channel shoes adapted to be staked in position on the subgrade and formed for permitting the joint mechanism to be seated therein. 7

It is an important object of this invention to provide an improved and simplified form of road expansion joint including a composite core anchored at one side to a concrete slab on one side of the joint and having load transmission units projecting therethrough for connecting the slabs on opposite sides of the joint by means of double dowels, said joint being provided with animproved copper cap having one side thereof imbedded between the composite core and one of the road slabs, while the opposite side of the cap is provided with an anchoring flange adapted to be imbedded in the opposite road slab to aiford a construction permitting opening and closing of the cap with the contraction and expansion of the road slabs due to temperature changes or other causes.

Other and further important objects of this invention will be apparent from the disclosure in the specification and the accompanying drawings.

The invention (in preferred forms) is illustrated in the drawings, and hereinafter more fully described.

On the drawings: 7

Figure l is a fragmentary side elevation of an expansion joint forming mechanism embodying the principles of this invention and disclosing the apertured core plate and the anchoring means mission units and beneath an improved closure cap forming part of the joint. 7

Figure 2 is an enlarged sectional view taken transversely through the expansion joint forming mechanism imbedded between concrete road slabs and supported on the road subgrade, and furthermore illustrating the joint cover cap anchored in one of the road slabs, said view also showing the supporting base of the joint staked in position to the subgrade.

Figure 3 is an enlarged fragmentary isometric View of a portion of the expansion joint cap, re-

moved from the joint, and illustrating the operation of the capin dotted lines.

Figure 4 is an enlarged fragmentary sectional view through the lower portion of a modified form of expansion joint provided with a modified form of supporting base for supporting the joint, on the road subgrade prior to the pouring of concrete.

Figure 5 is an enlarged fragmentary isometric view of another modified form of road expansion joint including both upper and lower closure caps, and also including supporting shoes for holding the joint unit supported in position upon a road subgrade prior to the pouring of concrete for imbedding the joint mechanism.

Figure 6 is a fragmentary vertical detail section through the upper'portion of an expansion joint using a modified form of top cap. l

As shown on the drawings: In the form of the expansion joint mechanism 7 illustrated in Figures 1 to. 3 inclusive; the reference' numeral I indicates a roadsubgrade on The improved expansion joint forming mechanism comprises a sheet metal filler or core plate 3, the lower portion or margin of which is bent o'utwardly to provide a side flange 4 which is doubled upon itself to project beneath and across the plane of the plate 3 to form a supporting base plate 5, the side margins of which are deflected downwardly to project into the subgrade I, as clearly illustrated in Figure 2. The supporting base, including the side flange 4 and the bottom plate 5, is provided with apertures at spaced intervals for the reception of mounting or retaining stakes 6, the lower tapered ends of which are driven into the subgrade I to hold the joint mechanisms in position prior to the pouring of concrete forthe formingv of the road slabs 2. Struck outwardly from one side of the core plate 3 is a plurality of longitudinal rows of anchoring wings or blades 1 so arranged that the anchoring blades of the upper row are staggered withcrespect to those of the lower row.

Cemented or otherwise rigidly secured to the opposite side of the metal core plate 3 is a preformed or precast plasticfiller board 8 formed of asphalt, sponge rubber, cork, or any other suitable compressible material, such, for example, as a compressible material known to the trade as Flexcel. Both the metal core plate 3 and the filler board 8 are provided with a plurality of spaced openings 9, with the openings of the plate 3 and the filler board 8 registering with one another, for the reception of load transmission units, one of which is engaged in each registering set of the openings 9. I

Each of the load transmission units comprises a pair of slidable interfltting load transmission sections, each of which comprises a strip of sheet metal which is deflected or formed to provide a small stop flange III, the end margin of which is deflected outwardly to form an anchoring lip or edge II. The opposite end of the plate forming the load transmission section is bent to provide a large flange I2, the end margin of which is deflected to form an anchoring edge or lip I3. The intermediate portion of the metal strip forming each of the load transmission sections is deflected or formed to provide an intermediate 8 section in the form of outwardly projecting loops I4 and I5 connected by means of a common plate I6 which integrally connects the two looped portions I4 and I 5, as clearly illustrated in Figure 2. The plate sections have the looped portions I4 thereof mounted to project into the looped per-- vided with side walls n which'close the sides of the looped portions I4 and extend beyond the sides of the'looped portions to form guide flanges I8. The looped portions I4, with the side walls I! and the side wall extensions I8, provide pockets or'sockets for the reception of the inner ends of oppositelydirected double dowel bars 19. The

outer projecting end of each of the dowel bars I9 is split longitudinally to provide anchoring fingers or blades 20 which are deflected upwardly and downwardly with respect to one another. The projecting intermediate portions of the dowel bars l9 are disposed between the guide extension flanges l8 forming parts of the side closure walls I! of the large looped portions I4 of the interfitting load transmission sections.

The upper portion of the expansion joint mechanism is closed by means of an improved metal cap constructed of copper or other suitable material, The closure cap seats over the upper marginal end of the filler board 8 and the main joint plate 3, as clearly illustrated in Figure 2. As illustrated in Figure 3, the closure cap comprises a deep or large side wall 2| and a small side wall 22, which normally are held in substantially parallel relation, with the upper margins of said side walls integrally connected by means of a top consisting of a straight top section 23 and an arched or convex top section 24, the outer margin of which is integral with the large side wall 2|. The lower margin of the small side wall 22 of the cap is deflected outwardly to form a straight narrow ledge or flange 25. The lower margin of the wide cap plate 2| is deflected outwardly at substantially right angles to provide a wide anchoring flange 26, the outer margin of which is curled over to provide an anchoring bead 27.

The inner ends of the dowel bars I9 are rigidly secured in the respective sockets I5 by spot welding or other suitable means. The split outer ends of the dowel bars project outwardly in opposite directions from the sides of the expansion joint and are imbedded in the concrete slabs 2, so that the telescoping or interfitting load transmission sections are adapted to have slidable movable with respect to one another with the contraction and expansion of the road slabs due to temperature changes.

The load transmission expansion joint mechanism may be assembled in the factory and shipped to location as joint units, with the load transmission units projecting through the joint plate 3 and the filler board 8, and secured thereto by means of wires or other suitable means. The closure top cap may also be engaged over the top margins of the plate 3 and the filler board 8, and may be Wired thereto. When on lo- .cation, a complete assembled joint unit is adapted to be seated upon the road subgrade I, supported by means of the base plate 5 through which the retaining stakes 6 are driven to hold the assembled joint forming mechanism in position. Concrete is then poured on opposite sides of the joint forming mechanism to form the road slabs 2 which imbed the joint mechanism, as illustrated in Figure 2. The concrete on one side of the joint embeds the anchoring flange 26 of the cap while the opposite side wall 22 of the cap and its projecting flange 25 are imbedded in the concrete of the opposite slab between the concrete and the outer surface of the core plate 3. As also illustrated in Figure 2, the core plate 3 has the anchoring blades 1 thereof imbedded in the concrete, so that the major portions of the joint mechanism are anchored to one of the road slabs. It will thus be understood that with the contraction of the road slabs 2, there is a tendency to open up the joint, pulling the joint plate 3 and the filler board 8 to one side with the contraction of one of the road slabs. With the contraction of the road slabs, the anchored double dowel bars move in opposite directions, causing movement of the interfitting load transmission sections in which the dowel bars are engaged. With the contraction of the road slabs, the top cap is opened, thereby keeping the top of the joint closed, since one side of the cap is moved from the full line position of Figure 3 into the dotted line position, due to the anchoring of the flange 26 in one of the road slabs, while the other and opposite side wall 22 of the cap is moved awayfrom the cap wall 2| due to the outward movement of the main joint plate 3 and the road slab to which it is anchored by means of the anchoring blades 1. Expansion of the road slabs 2 on opposite sides of the joint causes closing up of the joint forming mechanism with a compression of the filler board 8, and a movement of the side flanges 2| and 22 ofthe cap towards one another. The convex or arched portion 24 of the cap is provided to permit opening of the cap with the contraction of the road slabs, without causing downward crushing of the top edge of the filler board 8. v

Figure 4 illustrates a modified form of expansion joint mechanism similar in most respects to the joint mechanism illustrated and described in connection with Figures 1 to 3 inclusive of the drawings, with the exception that a main core plate 28 replaces the plate 3. Anchoring blades 29 are struck outwardly from the plate 28 for anchoring said plate in a concrete road slab on one side of the joint. The lower margin of the main plate 28 is bent at substantially right angles to extend underneath the filler board 8 to form a base or supporting flange 30, the outer longitudinal margin of which is slightly deflected downwardly as at 3|.

Figure 5 illustrates another modified form of road expansion joint comprising a main sheet metal core or filler plate 32 having anchoring lugs 33 struck outwardly from one side thereof. Cemented or otherwise rigidly secured to the opposite side of the main joint plate 32 is precast or preformed compressible filler or core board 34 constructed of Flexcel or other suitable material. The top and bottom longitudinal corner edges of the filler board 34 on the side opposite the plate 32 are beveled or chamfered at 35.

Both the plate 32 and the filler board 34 are provided with registering openings at spaced intervals for the reception of load transmission units which are constructed substantially the same as the load transmission units illustrated in Fig. 2, and have the corresponding parts identified by corresponding reference numerals.

In this form of the expansion joint, a closure cap is provided both on the bottom and on the top of the joint mechanism, said caps being constructed exactly alike and each comprising equal sized side walls 36 connected by a connecting or transverse wall 37. One of the side walls 38 is provided with a short projecting flange 38, while the opposite wall 36 is provided with a wide anchoring flange 39, the outer margin of which is curled to form an anchoring bead 40.

For supporting the joint forming mechanism in position upon a road subgrade, a plurality of supporting shoes constructed of sheet metal is provided at spaced intervals seated on the subgrade. Each of the shoes comprises an intermediate channel section 4l, the side walls or flanges of which extend upwardly and thenare bent downwardly upon themselves to form a double thickness at 42. Integrally formed on the 'outer walls on the lower margins of the side walls 42 are outwardly extending base flanges 43 provided with openings 44 for the reception of anchoring stakes adapted to be driven into the road subgrade to hold the supporting shoes in position to receive the bottom cap of the assembled road expansion joint forming mechanism, similar to the arrangement illustrated in Figure 2.

After the joint forming mechanism illustrated in Figure 5 is supported in position upon a road subgrade, concrete is deposited on opposite sides of the joint mechanism toimbed the same. The concrete slabs formed on opposite sides. of the joint are connected to one another through the load transmission mechanisms which project through the core members 32 and 34, so that loads applied to the slab on one side 'of the joint are adapted to be transmitted through the joint by means of the double dowel bars l9. When the concrete slabs on opposite sides of the joint contract, the joint is opened, and both the top and the bottom of the joint are maintained closed by the opening of the closure caps, the side flanges of which are adapted to be opened by the movement of the concrete slabs in which they are imbedded. The cap side flanges 36 being imbedded between the concrete and the plate 32 are movable with the concrete on that side of the joint and with the plate 32 to open one side of the cap, while the opposite sides of the caps are opened due tothe fact that the anchoring flanges 39 thereof are actuated by the contraction of the slab on the opposite side of the joint. The beveled edges 35 of the filler board 34 permit the corners of the caps where the side plates 36 of the anchoring flanges 39 join the plates 37 to deflect the portions of the plates 31 toward the beveled edges 35 to afiord an arrangement permitting opening and closing of the sides of the top and bottom closure caps on the side of the joint in which the anchoring flanges 39 of the caps are imbedded.

Figure 6 illustrates a modified form of expansion joint closure cap constructed of sheet copper or other suitable material, and comprises side walls 45 and d6 integrally connected by a convex or arched top wall 41, with the arched portion being positioned adjacent the side wall 45 and slanting down toward the opposite side wall 46. The lower margin of the side wall 45 is bent outwardly to form an anchoring flange 48, the outer edge of which is rolled to provide an anchoring bead 49. The lower edge of the side wall 45 is deflected outwardly to form a curved lip 50. With the contraction of the concrete road slabs, the slab in which the anchoring flange: 48 and the bead 49 are imbedded moves away from the filler board 8, causing the cap side wall 45 to move outwardly into an inclined position, thereby pulling the arched top wall 41 of the cap downwardly, permitting widening of the cap to compensate for the opening of the joint, and maintaining the top seal of the joint. Expansion of the road slabs causes compression of the filler board 8, with a compression of the cap top wall 4! raising the arched portion thereof.

It will, of course, be understood that various details of construction may be varied through a wide range without departing from the principles of this invention, and it is therefore not the purpose to limit the patent granted hereon otherwise than necessitated by the scope of the appended claims I claim as my invention:

1. An expansion joint forming mechanism comprising a metal core plate and a preformed plastic filler board cemented to one side thereof, said core plate and filler board having registering openings therein, interfitting double looped load transmitting sections projecting from opposite directions through the registering openings in the core plate and filler board, double dowel bars secured in loops of said interfitting sections and projecting outwardly in opposite directions therefrom for imbedding in the concrete slabs on opposite sides of the joint, means for anchoring the core plate and the filler board to one of the concrete slabs, and a base formed on the core plate and projecting underneath the filler board for supporting the joint forming mechanism in position on a road subgrade prior to the pouring of the concrete for forming the slabs between which the joint forming mechanisms are imbedded.

2. A road expansion joint comprising a metal core plate, a preformed compressible filler board secured to one side thereof, said core plate and filler board having registering openings therein, interfitting double looped load transmission sections projecting through the registering openings in the core plate and filler board, said sections including stop flanges contacting the outer faces of the core plate and the filler board, oppositely projecting dowel bars engaged in the double looped portions of the load transmission sections and projecting outwardly beyond the sides of the core plate and filler board, means for locking the dowel bars in the double looped load transmission sections','anchoring members formed on the projecting ends of the dowel bars, base members for supporting the road expansion joint in an upright position, a flexible closure cap engaged over the core plate and the filler board, and an anchoring means formed on one side of the flexible closure cap.

3. An expansion joint forming mechanism including in combination a composite core unit comprising a core plate and a core board secured to one another and having openings therethroug'h, load transmission units projecting through the core unit at spaced intervals, channel shoes for supporting the core unit at spaced intervals, means for securing said shoes in place, and a closure cap for the core unit comprising a pair of side walls of different depths, an anchoring flange integrally formed on the deeper one of the sidewalls, a projecting ledge integrally formed on the other of said side walls, and a top connecting the side walls and comprising a flat side section and an arched side section.

' formed on the large side plate, and a top connecting the side plates, said top comprising a flat side portion integral with the small side plate and an arched side portion integral with the large side plate to permit the large side plate to be swung away from the filler board by the spreading action of the'arched side portion of the cap top without causing crushing of the top of the filler board. 7

ROBERT R. ROBERTSON. 

